Fix bookmark request capture and discovery for X History

[zanedev]

Addresses #3: bookmark exports can fail with HTTP 422 after X moved bookmarks into History. Discovery now tries /i/history first, with /i/bookmarks retained as a fallback, and includes History in bundle discovery.

The extension captures operation-specific variables and field toggles alongside query IDs and feature flags, then replays those settings when exporting. The collector still controls the cursor, page size, and selected folder so a captured browsing request cannot skip the start of an export or select the wrong folder. Missing settings clear stale captures, and malformed settings fall back safely.

Validation:

• All 70 automated tests pass, including regression coverage for capture, request replay, route fallback, and cancellation.
• Syntax checks and git diff --check pass.
• A live user test collected bookmarks across multiple pages without HTTP 422 and downloaded the JSON successfully.

Remaining verification limits: the live scan ended on an empty page with a repeated cursor, so it correctly retained the partial-snapshot label. Full collection completeness is not established. Folder query IDs were unavailable in that session, so live folder export compatibility remains unverified. This change does not relax pagination guards or claim those separate limitations are resolved.